. Universal Serial Bus is an interface which allows computer to connect with peripherals and other devices.
    . USB can also be used to power devices like smartphones, tablets etc.
    . First released in 1996.

     USB Ports:

           . USB cables are connect to computer or other devices at USB ports.
           . In a desktop, we can find 2-4 ports in front and 2-8 ports in back.
           . In tablets or mobiles, USB port is charging port which works both for charging and data exchange.

     USB devices:

              . Most of the electronic devices we use have USB connection support.
           . It made us so easy to get connected to number of devices.
           . Before USB, devices are used to get connected using serial or parallel ports which requires extra circuit inside to get compatible.
           . Following are few devices which supports USB connection:
                         . Keyboard
                         . Mouse
                         . Printers
                         . Scanners
                         . Digital cameras
                         . Webcams
                         . MP3 players
                         . Smartphones
                         . Tablets

     Types of USB:

           . Type A:  Most USB cables have Type-A on one end which is to connect peripherals like keyboard, mouse to computer. 

           . Type B:  It is square type connector which is used to connect printers, scanners and other powered devices to computer.

           . Mini USB:  These are smaller than Standard USB. Mostly used in cameras and some other devices.
                               Smartphones, tablets used Mini USB before the usage of today's Micro USBs.

           . Micro USB:  These are much smaller compared to Mini USBs. 
                                 Currently used by all smartphones, tablets and other portable devices both for data and power.

           . Type C:  It offers higher power and data rates when compared to other types.
                           Adopted to use in laptops, some tablets and phones.